From f92b99b9dccb61760b345baf40ed37f59b91f8af Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 16 Oct 2007 23:30:59 -0700 Subject: [PATCH] fuse: update backing_dev_info congestion state Set the read and write congestion state if the request queue is close to blocking, and clear it when it's not. This prevents unnecessary blocking in readahead and (when writable mmaps are allowed) writeback. Signed-off-by: Miklos Szeredi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/dev.c | 8 ++++++++ fs/fuse/fuse_i.h | 5 ++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 3ad22be..ebc36f5 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -224,6 +224,10 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req) fc->blocked = 0; wake_up_all(&fc->blocked_waitq); } + if (fc->num_background == FUSE_CONGESTION_THRESHOLD) { + clear_bdi_congested(&fc->bdi, READ); + clear_bdi_congested(&fc->bdi, WRITE); + } fc->num_background--; } spin_unlock(&fc->lock); @@ -378,6 +382,10 @@ static void request_send_nowait(struct fuse_conn *fc, struct fuse_req *req) fc->num_background++; if (fc->num_background == FUSE_MAX_BACKGROUND) fc->blocked = 1; + if (fc->num_background == FUSE_CONGESTION_THRESHOLD) { + set_bdi_congested(&fc->bdi, READ); + set_bdi_congested(&fc->bdi, WRITE); + } queue_request(fc, req); spin_unlock(&fc->lock); diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 68ae87c..9f4603b 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -20,7 +20,10 @@ #define FUSE_MAX_PAGES_PER_REQ 32 /** Maximum number of outstanding background requests */ -#define FUSE_MAX_BACKGROUND 10 +#define FUSE_MAX_BACKGROUND 12 + +/** Congestion starts at 75% of maximum */ +#define FUSE_CONGESTION_THRESHOLD (FUSE_MAX_BACKGROUND * 75 / 100) /** It could be as large as PATH_MAX, but would that have any uses? */ #define FUSE_NAME_MAX 1024 -- 2.7.4